Astroblog

Obscured by Clouds. The rough and ready blog of a cloud benighted biologist and amateur astronomer. Astroblog will cover my interests in astronomy, biology and Life, the Universe and Everything.

Friday, December 23, 2005

A Competition!

Due to the Chrissy season, I will be unlikely to fire up any computer between now and Jan 9 while we visit rellies, eat to excess and view Christmas lights, so you are unlikely to see any new posts in this time.

But, filled with the joy of Christmas and getting the January Southern Skywatch up (and a good feed of prawns and chocolate fudge) I've decided to give away a copy of the January/February edition of Australian Sky&Space to one lucky person. All you have to do is describe you best skywatching activity over the Chrissy-New Year break. Leave your entry as a comment to this post, and on January 9 I will choose the comment that moves me the most (or is acclaimed by other commenters). Yes, it is insanely subjective, but hey I could just put them all in a hat and draw one out, or choose the post whose word count is a prime number.

Don't put any address details in the comment (people are watching you know). I will contact the winner via the comments to this post, they we can work out posting via private email later on.

Disclaimer: I don't get any revenue from this blog, so you won't be subsidising my retirement fund via your comments. I am a contributing editor to Australian Sky&Space, but I, like all my fellow contributing editors, are volunteers, we don't make any money from our articles, and this is not an official Sky&Space promotion, it's just me giving away a copy out of good cheer rather than cynically trying to drum up trade.

So, Merry Christmas (or your local equivalent celebration), a Happy New Year, keep safe on the roads and may you have clear skies!

Street party

Venus and telescope at street party.Christmas time sees the appearance of the street party. All the families on our street got together the chat, eat and imbibe their favorite drinks while the kids played cricket, or kicked footballs into trees (which I then had to climb to retrieve them). The afternoon twilight put on a nice show, while everyone enjoyed to warm conditions and fellowship. Eventually it got dark, and I dragged out the old portable refractor to show the kids Venus. Everyone, including the adults, were interested, especially as Venus is an amazing thin crescent of goodly size. Some people thought they were looking at the Moon. Mars was less successful due to cloud obscuring it, but a good session of planet gazing rounded off a fantastic street party.

The Beagle 2's possible collision site was picked up by Mars Global Surveyor, but there is no story on the MGS site at the moment. There are detailed images images at the Beagle 2 site.

Faint marking which seem to be a crash site, and things which might be the landing bags have been detected ib a crater close to the intended landing site, which was in a near-equatorial region called Isidis Planitia. Examination of the site with high resolution cameras on NASA's Mars Reconnaissance Orbiter will probably be required to determine if this really is the Beagle 2.

More on the Kitzmiller Case

The news of the Dover trial result is echoing around the world. New Scientist has a short story up already. It was on both ABC local news and Triple J, and has even turned up in the dear old Advertiser, hardly a cosmopolitan Journal.

You can download an audio file of the ABC story (realplayer and MP3's avilable at this link as well) and have a listen.

My favorite quote in the audio comes from the President of Christian Helpline who said Judges were not informed and needed to study the science of both sides. A sit happened there was an enormpus amout of science studied in the trial, it was quipped that everyone heard more about bacterial flagella than anyone would like to know. The key fact the emerged was that ID hadno science, just thinly described religious arguments slightly modified from old-style creationists.

Monday, December 19, 2005

Last Venus?

A photomontage of Venus waxing, as always, click on it to enlarge. My latest image is on the far right Venus is rapidly growing in size and rapidly getting thinner. Unfortunately it is also getting closer to the horizon, this image was taken during civil twilight. This may be my last Venus image in this series, as at the end of the week we are off to the beach for Christmas. Much clearer skies, but no place to power the imager, even if I had the room to put the reflector in the car (as it is there will be barely enough room for ourselves, let alone my telescope. By the time I get back, Venus may be too close to the horizon to image. Note that the ends of the crescent are slightly blurred, to to atmospheric turbulence stacking couldn't cancel out.Here's a Mars comparison too (once again click to enlarge). You can see Mars rapidly decreasing in size. Pretty soon it will be a waste of time to image. Especially with Summer hotting up, turbulence will be getting worse. Hopefully I can get some late night images of Saturn in the New Year.

Anglo Australian Observatory Photo stash

Wednesday, December 14, 2005

Aurora on Mars

Image Credit: David Brain & Jasper Halekas/SSLMars is just getting weirder. Mars Global Surveyor has detected hundreds of aurora on Mars. True, you can only see them in the ultraviolet, so you won't see the gorgeous colours you see on Earth, making a trek to Mars for the aurora enthusiast a bit of a waste. But the fact that they can be detected at all is amazing. On Earth aurora occur where magnetic fields funnel high speed Solar wind particles into the upper atmosphere. Mars has virtually no global magnetic field, but it does have some magnetic filed associated with patches of crust in the Martian Southern Hemisphere, where the aurora are seen. How Mars's weak magnetic field can cause funneling of charged particles is not clear.

What is it about the name Buffy?

Image Credit NASA/JPL-Caltech/T Pyle.That Tom, Stuart, the Bad Astronomer and ABC Science News all blog her near simultaneously. Buffy, of vampire slayer fame, is the temporary name given to a 500-1000 km lump of ice out at the outer edge of the Kuiper belt, following a fine old (well one year old) tradition that began with Xena and Gabrielle. Like most objects in the Kuiper belt, Buffy (otherwise known as 2004 XR 190) is at a large angle (47°) to the orbital plane of the planets as they go around the Sun. Unlike most objects in the Kuiper belt, Buffy has an almost perfect circular orbit. This has caused a lot of puzzlement and head scratching, because current theories can't explain how Buffy's orbit is so circular. For full details and links to a 3D orbital simulation see the Canada-France Ecliptic Plane Survey webpage on Buffy.

Tuesday, December 13, 2005

Lunar Mosaic

Here's a mosaic I made from my Sunday night imaging session. As always, click on the image to get a full size rendering. The image looks slightly weird as I didn't shoot as far along the northern limb as I did fro the Southern. I'm reasonably happy with how it turned out, given I was manually aligning in photoshop, and not using something groovy like autostich. You can see the rills in the lava flows of Sinus iridium, which is rather cool (you will have to click on the image to see this). What is disappointing is the way the intensity varies from frame to frame although I changed no settings (except in the very top images, when light cloud dimmed the images). I'll have to think of ways around that. Next time I think I'll try and attach the webcam to the Barlow lens. I wouldn't mind a ToUCam pro for Christmas, but I don't think Santa is getting me that :-(

Monday, December 12, 2005

Deck the halls

We put up our Christmas decorations tonight, we have a Pine tree growing in a pot which we drag inside each Christmas (and marvel that we haven't managed to kill it). It is decorated with a mixture of commercial Christmas lights and decorations lovingly made by the kids over the years. The Christmas tree at the Bettdesckererschnappender weisle's ancestral home is decorated with two generations of handmade trimmings, so there is a nice feeling of history and family continuity to it. As well, it is a nice antidote to the comercialization of Christmas to have this heartfelt family connection.

Our windows now twinkle with automated lights in our contribution to global warming, one or two neighbor's in our street will put up a string of flashing lights to get into the spirit of things. Next week we will wander down the streets that put in a serious effort. While they aren't as amazing as this house in the US (see the video here, it works best with the sound on) they will entrance the kids. Heck, we adults will be impressed too (and they don't make much addition to astronomical light pollution).

It's a bit strange celebrating Christmas in summer. All over Australia people are spraying fake snow over every available surface in temperatures that will cook eggs, and putting up pine trees and other European symbols of rebirth ready for sunreturn and when Wotan and Selipnir St. Nicholas and Rudolf ride out to deliver gifts to good boys and girls (and Knecht Rubrecht to fill the naughty ones' stockings with coal).

In the Antipodes Christmas falls just after the Summer solstice, when we begin our descent into winter. So it doesn't make much sense to perform the rituals associated with the shortest day of the year and the passing of winter in southern climes. It's rather ironic considering that Saint Nick, who is our Christmas icon, hailed from the Mediterranean Roman city of Myra (now in Turkey), an area not renowned for either snow, pine trees or fur trimmed red robes (sadly, the locals have put up a statue of Santa Claus, in full red trimmings). There have been desultory attempts to shift Christmas to the Southern hemisphere winter solstice, but the conjunction of the long, hot Summer holidays and Christmas is ingrained in the Australian psyche (after a family game of beach cricket what else would one eat on a 40 deg C day but roast pork and steamed plum pudding) and the fact that Christmas day is firmly associated with the birth of Mithra Yeshua ben Yusef.

In the end, it is all about Calendrics (you thought I was going to say peace and good will, didn't you). The marking of the transition of winter to spring, summer to autumn, has a powerful hold on the European psyche as these events were literally matters of life and death. Astronomy was a serious business, and there wasn't much of a role for amateur astronomers in those days. Here in Australia, where these transitions aren't as marked (or even identifiable, in the North, the seasons come as "wet" or "dry") the solstice were less important, and the seasonal transitions were often marked by non-astronomical means such as flowering of certain plants. In most of Australia, unlike Europe, where the winter/spring transition arrives like a hammer blow (one day snow, the next day tulips, was my experience in Berlin), you will always find something flowering, and it is more a matter of what and how much that subtlely shades the seasons (the flowering of the wattles on the Yarra meant that the end of winter was in sight, the flowering of the Jackarandas meant summer was on the way).

So, as you celebrate your sunreturn festival of choice, reflect that Astronomy played an integral part in determining when these festivals were held, and that our modern amateur past time with our telescopes and web cams has its roots in people anxiously waiting for the sun to rise over special notched rocks.

Happy Anniversary Opportunity

Panoramic camera image of sedimentary rock along the northwestern margin of "Erebus" crater. Some of these sediments were laid down in shallow water. Image credit NASAToday (December 12) Opportunity has been on Mars for a full Martian year. As I write, Mars rides three fingerwidths from the waxing Moon, peeking out between the wind tossed clouds (remember how yesterday it was 38 deg C? Today it's 18 C and markedly chilly with telescope shaking winds that frustrate an anniversary observation of Mars). Opportunity and Spirit have outlasted their 90 day design specifications to take magnificent panoramas, film whirling dust devils and provide definitive evidence that liquid water once flowed (or seeped) on Mars. Opportunity is poised on the edge of Erebus crater, ready to examine a wealth of sedimentary layers and explore more of Mars's hydrological history. Unfortunately, Opportunities robotic arm is stuck. Unless it can be unstuck, the amount of information it can reveal will be limited.

Still, it can keep on taking great pictures and do other science experiments, and it has done so much already. Opportunity and Spirit, I salute you.

Sunday, December 11, 2005

Not so Great Venus and Mars

Not so great images this time, as I said below, the temprature was 38 deg Celcius, great for swimming (which we did to end up our Sandy Creek adventure) but lousy for seeing, Any detail in Mars was blurred out, and Venus was all over the place, looking more like a writing snake than a planet. The turbulence didn't do anything to detract from Venus' size (drop a weeks observing and the planet zooms up on you) or it's obvious crescent shape though. Compare this with the images I took on November 27 and you will see how much Venus has grown and changed phase.

Some Moon Shots

As an antidote to the small blurry planet images I usually present, here are some reasonably nice Moon shots taken tonight. Despite the temperature getting to 38 deg Celsius today, and the atmosphere doing a jig on me, I think they came out rather well (at least compared to the low-cost astrophotography image). You can even see ejecta rays.

Sandy Creek Redux

Venus setting over the Sandy Creek Youth Hostel (as always, click to enlarge).I love going to Sandy Creek. Well, as I've written before, I don't so much love the going to part. Smallest one going beserk, the rushing around to leave on time, the discovery down the road that some vital toy or game has been left behind. That I could live without. But being at Sandy Creek YHA is a delight. Clear skies, beautiful bush walking tracks just outside your front door of a variety of lengths that the kids can do at least a bit of walking on. The variety of animals that live around you is pretty astonishing too.

Last time we were at Sandy Creek the fields were lush and green, wattles and orchids were flowering, and Venus, Jupiter and Spica floated above the roof. This time the fields were burnt blond, broom and grevillias were flowering and Venus kept solo vigil above the youth hostel chimney.

They have been putting in new walks at Sandy Creek to replace the old eroded walks. We stumbled over part of the new tracks last time. This time we did the new Wren walk all the way around. Saw some large Euros (a kind of wallaby). In the afternoon we played bush cricket, got boomerangs stuck in the trees and futilely tried to fly kites. Pointed out Venus in the daylight and saw it as a crescent in binoculars.

Then we had a big birthday bash for the Bettdeckererschnappender weisles hemi-semi-demi cousin. Risoto and chocolate cake with sparklers, the lot.

After that I showed the kids and the adults crescent Venus, the Moon (Copernicus really vividly sharp, and mountains casting long shadows), Mars (it was pretty much a rudy disk in my 50 mm refractor) and Orions Nebula. With the Moon past first quarter the nebula wasn't spectacular, but the skies were darker than Largs North without the Moon, so it was pretty good. The adults were more entranced that the kids, because the kids were pretty well exhausted. But everyone enjoyed looking at the sky.

We finished off with coffee on the Veranda, watching the lowering Moon silvering the fields before us. What a way to spend the weekend.

Low Cost Astrophotography

There are lots of ways people with simple tools can do astrophotography. With the advent of cheap digital cameras, people can participate in imaging our skies as never before. I've written about solar projection before, where you can project the Sun's image onto a screen and photograph that to your hearts content. Another technique is simplicity itself. Focus your digital camera to infinity (landscape mode often will do this automatically), put the camera directly on the eyepiece of your telescope or binoculars and hey presto!

You get a nice, fuzzy, out of focus image like this one I took of the Moon after half-an-hours sweating.

If you have a very stable telescope mount and no wind (which I didn't have when I took this) and don't shake much when holding your camera (I do). Then you can actually get quite nice pictures. You are pretty much limited to the Moon, Venus at it's brightest and Jupiter at opposition, but you can take reasonable images with fairly simple equipment (my telescope here was an elderly 50 mm refractor mounted on at camera tripod). If you have a spare camera tripod, mounting your camera on the tripod makes taking non-shaky images a whole lot easier. If you want to get fancy, you can build or buy adaptors to mount your camera directly on your telescope. The latter site has a nice tutorial on adapting digital cameras to telescopes.

Talk amongst yourselves

With a Coronal mass ejection on the way, a naked eye sunspot, and lots of Venus gazing to do, I'm off to Melbourne for the Annual Australasian Society for Clinical and Experimental Pharmacology meeting, where my students will present posters on determinants of neuronal growth and novel ways to comabt oxidative stress. I'll co-chair a meeting on signal transduction. It will be very interesting, and I won't have much time for astronomy. I'm unlikely to do anything on the blog until Thursday so see you then.

Friday, December 02, 2005

Sunspot 826 produces CME, aurora to follow?

Image Credit SOHOWell, no sooner had I posted the Sunspot 826 post, but it erupted in a series of flares, (the image shows the first M class flare) ending in an M6 class flare (big). The strength of this CME is not yet known, but it is likely that at least some of this material will hit Earth in the next 24-48 hours, with the possibility of aurora.

People in Tasmania and Southern Victoria should be on the lookout for aurora after sunset on the 3rd and 4th of December. Aurora can strike anytime, but looking south after local midnight is often the best. At Victorian latitudes you will usually see a pink, shifting glow with faint rays, you won't see the magnificent sheets of aurora you can see in Tasmania.

More Binocular Venus

Inspired by Peter's recent comment I went out an had a look at daytime Venus (if you folks are going to try this, make sure you know where Venus is and that the Sun is blocked by a large object such as a wall or building so you don't accidently view the Sun through binoculars and severely damage your eyes).

Venus was quite easy to see in binoculars. I braced my arms against the back of a chair so there was not too much wobble. In my badly-in-need-of-a-professional-clean-and-tune up 10x50's Venus was a tiny crescent. In my Dick Smith 10x25's I convinced myself that it was crescent shaped.

The clouds cam over shortly after sunset, so I couldn't determine exactly when the glare got too much. But it looks like if you want to see crescent Venus in binoculars, daytime is the go. As Venus will increase form 35 to 50 arc seconds during December, the chances of binocular Venus is quite good.

SETI rebuffs Intelligent Design

Inteligent Design, the idea that David Brin writes non-ficton (seriously, do you think ID promoters would be giving so many talks to church groups if they honestly believed we are the descendents of Slaver food yeast?), often makes reference to SETI as an activity that makes use of a "design inference". William Dembsli uses SETI as an example quite often, although he uses the setup in Carl Sagan's science fiction novel "Contact", rather than what the real SETI does. Now the good folk at SETI have written a nice article pointing out how ID proponents misuse SETI.

Sunspot 826 Ahoy!

Image credit SOHOThe Sun had gone quiet on us after the excitement of sunspot 822, but in the past two days sunspot 826 has expanded in size from the inconspicuos to around the size of Saturn. This one will be interesting to watch with safe solar projection techniques as it rotates across the Sun's face. 826 has also fired off a C and M class flare, so there is a small chance we might get aurora from this one.

Thursday, December 01, 2005

The Lost Oceans of Mars

Image credit ESAThis weeks issue of the journal Nature is packed with news of interest to the Astronomical community. Mars rates high on the list. Firstly, the MARIS radar array, which is seeking buried water, appears to have found ice in a mid-latitude crater. This could be remanants of water that once flowed through Valles Marineris. MARIS will start seeking water in earnest in the coming weeks.

Image Credit ESAAlso, the OMEGA spectrometer has found evidence of clays in the old uplands of Mars. While the Mars rovers and orbital reconnaissance have found abundant evidence of past water on Mars, it appears to have been acidic, which is not conductive to forming clays. The finding of clays in the oldest terrains suggest that at early periods, between 4.0-3.5 Billion years ago, Mars was warm and wet and somewhat Earth-like, then as Mars evolved the water became salty and acidic before disappearing.

In other news Hayabusa has almost certainly got asteroidal samples, but it's engines seem to be playing up, casting doubt on a return to Earth. There is also the first in-depth reports of the Titan mission, but these are all subscriber only (so no links). I'll try and summarise later on, but particularly interesting is that the aerosols in Titan's atmosphere are complex, nitrogen containing organic compounds.

Binocular Venus Challenge

Okay, so I went out with both my 10x50 and 7x50 binoculars and had a look at Venus. It sort of looked longer than it was wide, but there was so much glare and internal optic reflections that I couldn't be sure. Perhaps if you look in the very early twilight, when there is less glare from ultrabright Venus you can see the crescent. I'll have a look this evening if the cloud goes away. Has anyone else seen Venus as a cresent in binoculars? Astronomical grade 25x150 super-binoculars don't count.